Hypolimnas bolina is a Nymphalid butterfly having a west to east distribution from Madagascar to Easter Island, and a north to south one from Japan to Australasia. It is highly migratory in some areas. In much of the western part of its range the female is both monomorphic and a mimic of Euploea. Further east it is frequently polymorphic with the majority of the forms being non-mimetic. The polymorphism is sex-limited to the female and controlled by two unlinked loci, one with two allelomorphs, E and e, determining the extent of the dark pigmentation, the other with three allelomorphs, P, Pn and p, determining the presence and distribution of orange-brown. Only butterflies of the genotypes EEpp and to a lesser extent Eepp are satisfactory Batesian mimics of their Euploea models. The details of the mimetic pattern are under multifactorial control, following those of their local model, as is much of the variation within the non-mimetic forms, particularly with regard to the distribution of white and blue scaling.